Experimental studies of the placebo response

The critical evaluation of new drugs or remedies against inert substances or nonspecific procedures has led to the recognition that responses to a placebo are important in their own right. Such responses may be dramatic and persistent and they can be associated with quite definite physiological changes (Wolf and Pinsky, 1954). The placebo response may well be an important component of many established treatments both physical and psychological, and does in itself constitute a means of therapy (Roberts and Hamilton, 1958; Gliedman et al., 1958).

EFFECTS OF A DEPRESSANT DRUG AS MODIFIED BY EXPERIMENTALLY-INDUCED EXPECTATION

Objective and subjective reactions to drug and placebo treatments were studied in 15 healthy Ss under three conditions: (1) 200 mg. Pentobarbitone introduced as a depressant drug, (2) 200 mg. Pentobarbitone introduced as a drug the actions of which were not known to E, and (3) a placebo introduced as a depressant drug. Mean time-response curves showed that pulse rate, objective and subjective reaction speed, and subjective wakefulness were decreased by all treatments. The greatest effects were produced by Pentobarbitone introduced as a depressant while Pentobarbitone alone was, on the whole, less effective than the placebo introduced as a depressant drug.

IMIPRAMINE IN THE TREATMENT OF NOCTURNAL ENURESIS OF CHILDHOOD

A double-blind study of the use of imipramine in the treatment of nocturnal enuresis is reported. The subjects were twelve children aged six to 12 years in a children's psychiatric hospital. The drug (25 mg) or placebo was administered at 8.00 p.m. for two or four weeks at a time, the trial extending from 16 weeks to 32 weeks. For the group as a whole, the number of enuretic nights declined from 46.75% on placebo to 31.75% on drug, a reduction of 32.09%. The average enuresis per child declined from 47.25% to 30.75%, a reduction of 34.92%. Three children showed a significant response to placebo, one of these became virtually dry. Seven of the subjects showed a signficant response to the drug, with reduction of enuretic nights of 25% or more in all, of 50% or more in three and of 70% or more in two. Relapse occurred on discontinuing the drug.

In addition to the fall in enuresis each time drug was given, an over-all decrease in enuresis occurred throughout the trial, not due to spontaneous improvement. It is suggested that this results from the full effects of the drug being somewhat delayed and taking some time to wear off.

Observations on the time at which enuresis occurred showed that most commonly only incidents after 1 a.m. were reduced, suggesting that for this group earlier administration of the drug may be desirable. In only one subject was enuresis before 1 a.m. accompanied by an increase in incidents after 1 a.m. and for such cases an increased dosage may be effective. No side effects from the drug were observed.

A consideration of the mode of action of the drug is presented and it is concluded that it may act by diminishing uninhibited bladder contractions by its autonomic diencephalic action. Previous reports on the treatment of enuresis by imipramine are reviewed together with a brief review of controlled studies of other drugs which have appeared in the past decade.

It is concluded that imipramine is a useful drug in the treatment of enuresis in psychiatrically disturbed children.